add rysnc immich library sync service

modules/homelab/services/immich/default.nix

@@ -44,6 +44,11 @@ in {
       type = lib.types.nullOr lib.types.str;
       default = "immich-server";
     };
+    library_sync_dir = lib.mkOption {
+      type = lib.types.str;
+      default = "/holocron/users/blake/pictures/library";
+      description = "set directory to automatically rsync library to storage pool";
+    };
   };
 
   config = lib.mkIf cfg.enable {
@@ -76,6 +81,31 @@ in {
       #settings.server.externalDomain = "https://photos.blakedheld.xyz";
     };
 
+    systemd.services.immich_library_sync = {
+      description = "twice daily sync immich library to holocron";
+
+      serviceConfig = {
+        Type = "oneshot";
+        User = service;
+      };
+
+      script = ''
+        rsync -a --delete \
+          --chown=blake:blake \
+          /var/lib/immich/library/blake/ \
+          /holocron/users/blake/pictures/library/
+      '';
+    };
+
+    systemd.timers.immich_library_sync = {
+      wantedBy = ["timers.target"];
+      timerConfig = {
+        OnBootSec = "5m";
+        OnUnitActiveSec = "12h";
+        Persistent = true;
+      };
+    };
+
     # override umask to make permissions work out
     #    systemd.services."${toString service}-server".serviceConfig = {
     #      UMask = lib.mkForce "0007";